Tuesday, January 08, 2013

IBM donated Lego Mindstorm NXT kits and gave them to local high schools in Rochester MN, and had a competition at the Rochester Technical college for elementary up to high school. A lot of these rigs didn't work right, but Henry's worked just fine. These had to ride on a monorail, use an optical sensor to pick up "cargo" and drop them off, and then quickly reprogram to do a slightly different task.

Got this at Fry's as I was looking for something that you could use to use off the shelf batteries to charge my phone, which is a big htc evo-style phone. I thought it was curious that every unit on the pegs was a return, but I figured I would try it anyway. It only charges for a few minutes and then quits.Interesting digital voltage trick to get 4.5V out of 2 1.2v batteries. I did observe it charge from 20 to 30 percent, but then it quits. The unit charges the 2 AA nimh batteries when plugged into the wall. You can feed it other AA batteries chargeable or alkaline as well, though they may not work as well.

Much better solution are big battery packs like lenmar which you charge first or simply carrying extra battery packs and swapping them in if you have a phone which still lets you replace the battery. My HTC Touch Pro 2 goes through 2 batteries a day plus one I keep in charge with even a little bit of email or intenet use.,

How to Charge Any USB Device with AA Batteries – Make Your Own Battery Pack!!!

Posted by gregd1024 on December 23, 2007

I recently had this weird idea to take apart a USB cable, solder the +VCD and ground wires to a “AA” battery holder, slap in some batteries, and see if the contraption would power/charge my cell phone. Well I just tried this, and it worked! Check it out:

And since it takes four 1.5V “AA” batteries outputting six volts total instead of the standard 5V from the phone’s AC adapter, this homemade battery pack charges the phone faster!

I want to tell you how to make your own. It’s really simple. First, you’ll need these supplies (all from Radio Shack):

Wire cutter/stripper.

Four lithium ion AA batteries (Nickel Metal Hydride’s [NiMH] should work good too).

Any cable with a female “4 Pin Mini-USB” or “5 Pin Mini-USB” connector on one end.

Solder and soldering-iron (not shown).

The battery holder needs to carry four “AA” size batteries. Make sure you get a USB cable that you don’t care about because you’ll be destroying it. The wire strippers must do really small gauges (24 – 26 AWG). I would highly recommend using the thickest USB cable you can find or else the internal wires might be too small to strip